Several living organisms exhibit remarkable moisture-resistant adhesion to a variety of substrata.1,2 For example, mussels attach to a variety of substrates under wet and turbulent environments using unstructured mussel holdfast proteins,2 and marine invertebrates and microorganisms achieve interfacial adhesion and self-protection using functional amyloid proteins.3,4 Natural underwater adhesives, particularly the mussel holdfasts, have inspired the development of catechol-containing or catechol-analogue-containing peptides,6 polymers,7 and recombinant mussel-mimic adhesive proteins,9 with multiple applications ranging from surface coatings to medical adhesives.2,7,10 To date, however, biomimetic adhesives have not yet achieved or exceeded the strong wet bonding strengths, robustness, or functionalities of their natural counterparts.